The most important feature in a child equipment is the superior capability of safety and comfortableness for the infant. It is particularly critical to protect the life and brain of an infant in the first several months of life whose brain is not yet completely developed.
Although an infant is often thought to be a miniaturized analogy with a grown up, the faculty for life is still immature. There is a possibility that any application of a concept similar to that for a grown up, if taken improperly, may produce harmful aftereffects. For example, consider the case of an external impact applied due to a car accident. Since a baby's head is relatively heavy and the muscle of the neck supporting the head is weak, the head of a baby is more susceptible to impact than other regions of the body.
The skull, the cerebral blood vessel, the cervical spine and the like are not yet mature from the standpoint of structure and function. For example, consider the case of an infant before the age of one year, particularly a baby in the first six months of life. Although a baby of such age carried upright in one's arm may be cradled gently up and down, a strong swing in the back and forth direction or left and right direction may cause cerebral hemorrhage to produce aftereffects or even result in death.
In child equipment such as child seats, baby carriages, baby beds, baby carriers and the like, the provision of a structure that can sufficiently guard the infant's life and brain is an extremely important factor to truly protect an infant taking into consideration the physiological attribute characteristics.